Yamaha YZF-R125 Owners Manual: Motorcycle care and storage

Troubleshooting charts

Starting problems or poor engine performance Starting problems or poor engine performance Engine overheating WARNING Do not remove the radiator cap when the engine and radiator are hot. S ...

Matte color caution

NOTICE Some models are equipped with matte colored finished parts. Be sure to consult a Yamaha dealer for advice on what products to use before cleaning the vehicle. Using a brush, harsh ch ...

Other materials:

Checking the primary drive gear
1. Remove: Primary drive gear Refer to "BALANCER GEAR" on page 5-53. 2. Check: Primary drive gear Damage/wear  Replace the primary drive gear and clutch housing as a set. Excessive noise during operation Replace the primary drive gear and clutch housing as a set ...

Checking the spark plug
1. Remove: Right side cover Refer to "GENERAL CHASSIS" on page 4-1. 2. Disconnect: Spark plug cap 3. Remove: Spark plug CAUTION:Before removing the spark plug, blow away any dirt accumulated in the spark plug well with compressed air to prevent it from falling ...

Checking the rectifier/regulator
1. Check: Rectifier/regulator output voltage Out of specification → Replace the rectifier/ regulator. a. Set the engine tachometer to the spark plug lead. b. Connect the pocket tester (DC 20 V) to the rectifier/regulator coupler as shown. Positive tester probe red "1" Negat ...